This invention is directed to a self-propelled pickup device for picking up materials, such as manganese lumps, lying on the bottom of the sea, including horizontal cutting tools cutting into the sea bottom and a cooperating conveyor. More particularly, the present invention is directed to a substantially improved pickup device of this type.
A known device of this type travels on the bottom of the sea by means of a caterpillar drive. This known device is provided with two coaxially arranged and oppositely rotating worms at its front end, considered in the driving direction. The receiving part of a bucket conveyor terminates between these worms, and the bucket conveyor feeds the material to an elevator or an elevating conveyor. Baffle plates are arranged behind the worms, and are adapted to the form of the worms, and these baffle plates enhance the transportation of the material by the worms to the bucket conveyor.
In this known device, there is the risk that the materials engaged by the worms, or the materials lying in the proximity of the rotating worms and beginning to move, will penetrate into the solid ground or move out of the conveying range of the worms, so that these materials are not gripped and thus are lost. Another disadvantage of the known device is that the caterpillar drive is not effective, due to the insufficiently solid surface of the ground. Such an arrangement is shown, for example, in U.S. Pat. No. 3,314,174.
There is also known as underwater scraper with a cutting asssembly scraping the bottom of the sea, and with the cutting assembly consisting of a cutter, carried by a linkage, with the linkage being secured on the traveling gear for pivoting about a horizontal axis. The conveyor consists of a conveyor wheel with edges extending upwardly and outwardly, and a conveyor belt which is guided, in the range of the material to be conveyed, between the edges of the conveyor wheel. The conveyor wheel is provided with movably mounted spades which are controlled by a cam disc guide arranged inside the wheel in such a manner that the spades can extend substantially in the radial direction through the space formed by the conveyor belt. In this arrangement, the spades penetrate into the space in front of the cutters, so that there is also a risk that the materials to be conveyed will begin to move before they are engaged by the pickup device and thus are lost. This arrangement is shown in German DOS 2,055,410.
A further known self-propelled pickup device is provided with three traveling rollers, and consists of suction heads with suction channels provided in the forward part in the direction of motion, these suction channels leading to a suction device. Flexible extensions, spaced from each other in order to facilitate the loosening and pickup of the material lying on the bottom of the sea, are arranged at the front edge of the suction heads. This arrangement, which is disclosed in U.S. Pat. No. 3,504,943, also has the disadvantages of the already-mentioned known pickup devices.